code: def __del__(self):
      logging.info(f"withhold fold has {self.fold_cnt}")
  
file_path: ParlAI/projects/trollhunting/mutators/k_fold.py
imports: from typing import List, Optional
  from parlai.core.message import Message
  from parlai.core.mutators import ManyEpisodeMutator, register_mutator
  from parlai.core.opt import Opt
  from parlai.core.params import ParlaiParser
  from parlai.utils.data import DatatypeHelper
  import hashlib
  import parlai.utils.logging
label_desc: Use image node_id 2 for calling the KFoldReleaseOnValidMutator obj's underlying member method code with example usage: obj.__del__() without return types